1. The greatest service, by which you will go back to Godhead

    So I simply request you, you are doing the greatest service to the world by giving up everything for preaching this Krishna philosophy, you please continue just as you are doing. Introduce this process of chanting Hare Krishna, distribute as much prasadam as possible, and if possible see that all our books are translated and distributed as widely as possible. This is the greatest welfare activity, and for engaging yourself and others in this way, certainly you will go back to home, back to Godhead. 

    From Srila Prabhupada's letter to Hanuman; Bombay, 4 October, 1973